Apple came out swinging when it announced its latest MacBook Pro update earlier this month. In preparation for the launch, the company seeded souped up versions of the notebook with a diverse array of creative professionals, who happily discussed the ways in which the new specs have improved their workflows.

The reviews have been largely positive, as well — our own included. The laptop performed admirably and racked up some impressive benchmark scores in our testing that were in line with the performance boosts recorded by Geekbench itself. But in amongst those reviews, Dave “D2D” Lee reported some troubling findings in a video titled “Beware the Core i9.”

The YouTuber found that exporting video with Premier Pro actually took longer on the new models sporting a top of the line Core i9 than they did on last year’s model running an i7. Counterintuitive to say the least — and something that appeared to be some sort of system throttling, in order to deal with overheating while exporting. In the video, Lee speculated that the laptop’s chassis (unchanged from the previous generation) simply couldn’t cool the i9 properly.

“It was an issue that was unique to this year’s version, particularly the i9,” Lee told TechCrunch, in a followup interview this week. “It only occurred because this particular CPU is as power-hungry as it is. That puts it over the top.”

Benchmarks often only tell part of the story. They work well as for sterile, laboratory testing, but don’t always offer a decent stand-in for real world usage. Among other things, workflows vary a good deal from case to case and user to user. Lee says he was surprised to find that his own workflow was taxing to the system compared to the ones others shared in the online community after the initial video was posted.

Even so, as Apple makes a major push to recapture the hearts and minds of creatives, it will require systems that can handle just about anything creatives can throw at it. Lee tells TechCrunch that both Apple and Premier Pro-producer, Adobe, were quick to reach out after the video was posted.

“It was impressive to see how quickly they worked with the community find out what was going on,” he says. “The first step was to try to replicate this, to find out what was causing it. When they figured that out, I think they tried to figure out how to resolve it.”

It seems that Apple’s initial testing simple didn’t account for the specifics of the workflow Lee put the system through. In the intervening days, however, Apple says it has identified the issue and will be releasing a fix in an update to MacOS High Sierra rolling out today.

The company apologized for the bug fix in a statement provided to TechCrunch,

Following extensive performance testing under numerous workloads, we’ve identified that there is a missing digital key in the firmware that impacts the thermal management system and could drive clock speeds down under heavy thermal loads on the new MacBook Pro. A bug fix is included in today’s macOS High Sierra 10.13.6 Supplemental Update and is recommended. We apologize to any customer who has experienced less than optimal performance on their new systems. Customers can expect the new 15-inch MacBook Pro to be up to 70% faster, and the 13-inch MacBook Pro with Touch Bar to be up to 2X faster, as shown in the performance results on our website.

The company notes that a majority of users experience performance gains — which we can certainly confirm in our own testing. The issue at hand appears to have been something more complex and rarer than just a system shutting down or cutting back on power from overheating. The company is recommending users install the Supplemental Update to avoid performance slow downs during taxing actions.